1. Field of the Invention
The present invention is related to a card with a main cylinder on which fleece to be carded is lying, and with a doffer roll, also known as a doffer, with which the carded fiber layer is taken over as fleece. The card is provided with a diverging gap between the main cylinder and the doffer roll that extends over the whole width of the main cylinder, with an air guide plate which forms a diverging gap with the surface of the main cylinder so that the air flowing into the diverging gap is guided by the air guide plate in such a way that the transfer of the fleece to the doffer roll is assisted.
2. Description of the Related Art
An air guide plate of the above-mentioned type has already been provided on Applicant's own commercial carding machines in order to assist the transfer of the fiber fleece from the surface of the main cylinder to the doffer roll.
Such machines, however, are a type in which the air guide plate is provided as a rim of the cover plate, as seen in the peripheral direction of the main cylinder in the immediate carding zone, and which is arranged with a predetermined spacing against the surface of the main cylinder and the doffer surface. The exact setting of the part has to be adjusted each time by means of time consuming trial and error, and is only applied to predetermined parameters, such as the main cylinder rotational speed, for example, and to the material to be processed.
The air carried along the main cylinder surface is thereby conveyed in the existing converging gap between this air guide plate and the main cylinder surface and subsequently in the narrowest gap; that is, in the gap between the above-mentioned cover plate and the main cylinder surface.
The disadvantage of this arrangement is that the air relationship in the diverging gap between the main cylinder surface and the doffer surface and, likewise, on the free end of the air guide plate are different, depending on the air current in the gap between the surface of the main cylinder and the cover plate, which has a variable effect on the guiding of the fleece from the surface of the main cylinder to the surface of the doffer roll.
This effect changes, for example, with the thickness of the main cylinder clothing and the doffer clothing, with the peripheral speed, and also with the air relationship in the intermediate carding zone between the surface of the main cylinder and the plate covering this surface.